Seattle Genetics, Inc. (Nasdaq:SGEN) today announced dosing of the first patient in the phase 2 innovaTV 207 clinical trial evaluating the activity, safety and tolerability of tisotumab vedotin as monotherapy in selected solid tumors with high Tissue Factor expression. Tissue Factor is overexpressed in a broad range of solid tumors that are associated with a poor prognosis. Tisotumab vedotin is an investigational antibody-drug conjugate (ADC) designed to target the Tissue Factor antigen on the surface of cancer cells and deliver the cell-killing agent monomethyl auristatin E (MMAE) directly inside cancer cells. Tisotumab vedotin is being developed in collaboration with Genmab A/S. The potentially pivotal phase 2 trial innovaTV 204 evaluating tisotumab vedotin for patients with cervical cancer who have relapsed and/or progressed after standard of care treatment was recently initiated.

“The initiation of the phase 2 innovaTV 207 basket trial will enable us to explore the safety and activity of tisotumab vedotin in several tumor types where Tissue Factor is also expressed and is intended to inform a potentially broad development program that maximizes the opportunity for this ADC beyond cervical cancer,” said Roger Dansey, M.D., Chief Medical Officer at Seattle Genetics.

The phase 2 innovaTV 207 trial is a global, multicenter, open label basket trial that will enroll up to 200 adult patients with relapsed, locally-advanced or metastatic disease in one of four cohorts: colorectal cancer, squamous non-small cell lung cancer (NSCLC), pancreatic adenocarcinoma, and squamous cell cancer of the head and neck (SCCHN). Patients will be treated with single-agent tisotumab vedotin every three weeks. The primary endpoint of the trial is confirmed objective response rate (ORR) defined as the proportion of patients who achieve a confirmed complete or partial response. Key secondary endpoints include confirmed and unconfirmed ORR, disease control rate, duration of response, progression-free survival, overall survival, safety and tolerability.

Tisotumab vedotin is an antibody-drug conjugate (ADC) composed of Genmab’s human antibody that binds to Tissue Factor and Seattle Genetics’ ADC technology that utilizes a cleavable linker and the cytotoxic drug monomethyl auristatin E (MMAE). In cancer biology, Tissue Factor is a protein involved in tumor cell signaling and angiogenesis. Based on its high expression on many solid tumors and its rapid internalization, Tissue Factor was selected as a target for an ADC approach. In an earlier study, tisotumab vedotin demonstrated an encouraging response rate and manageable safety profile in patients with relapsed, recurrent and/or metastatic cervical cancer.

Tisotumab vedotin is being co-developed by Seattle Genetics, Inc. and Genmab A/S.

About Seattle Genetics

Seattle Genetics, Inc. is an emerging multi-product, global biotechnology company that develops and commercializes transformative therapies targeting cancer to make a meaningful difference in people’s lives. ADCETRIS® (brentuximab vedotin) utilizes the company’s industry-leading antibody-drug conjugate (ADC) technology and is currently approved for the treatment of multiple CD30-expressing lymphomas. Beyond ADCETRIS, the company has established a pipeline of novel targeted therapies at various stages of clinical testing, including three in ongoing pivotal trials for solid tumors. Enfortumab vedotin for metastatic urothelial cancer and tisotumab vedotin for metastatic cervical cancer utilize our proprietary ADC technology. Tucatinib, a small molecule tyrosine kinase inhibitor, is in a pivotal trial for HER2-positive metastatic breast cancer. In addition, we are leveraging our expertise in empowered antibodies to build a portfolio of proprietary immuno-oncology agents in clinical trials targeting hematologic malignancies and solid tumors. The company is headquartered in Bothell, Washington, and has a European office in Switzerland. For more information on our robust pipeline, visit www.seattlegenetics.com and follow @SeattleGenetics on Twitter.

Forward Looking Statements

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the therapeutic potential of tisotumab vedotin, its possible benefits and uses as monotherapy, the referenced phase 2 clinical trial, trial design, targeted patient population and enrollment numbers, and the intention of using the data therefrom to inform a potentially broad clinical development program for tisotumab vedotin in collaboration with Genmab, including evaluation in multiple solid tumor types, and the company’s intention to become a global multi-product oncology company. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include the inability of tisotumab vedotin to show sufficient activity in the clinical setting referenced above and the risk of adverse events of tisotumab vedotin, delays in planned clinical trial initiations, enrollment and conduct, obtaining data from clinical trials, and anticipated regulatory submissions and approvals in each case for a variety of reasons, including the difficulty and uncertainty of pharmaceutical product development, unexpected adverse events and/or adverse regulatory action; the inherent uncertainty associated with the regulatory approval process, including the risks that submissions for approval may not be accepted for filing by, or ultimately approved by, the FDA in a timely manner or at all, and that the company may otherwise experience a more lengthy and costly regulatory approval process than anticipated; the potential for newly-emerging safety signals, failure of clinical results to support continued development or regulatory approvals; failure to properly conduct or manage the company’s clinical trials; and possible, required modifications to clinical trials and the inability to provide information and institute safety mitigation measures as required by the FDA or other regulatory authorities from time to time in which case our clinical trials may be delayed or discontinued. More information about the risks and uncertainties faced by Seattle Genetics is contained under the caption “Risk Factors” included in the company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2018 filed with the Securities and Exchange Commission. Seattle Genetics disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.